Field of the Invention
The present invention relates to an image forming apparatus, and a control method therefor, and in particular to an image forming apparatus capable of updating firmware, and a control method therefor.
Description of the Related Art
Conventional image forming apparatuses are capable of connecting to a network and have an image storage function and a file service function of offering image data to a PC as well as an image printing function and an image sending function, and hence they have functions similar to those of computer equipment such as PCs and server equipment connecting to a network.
In PCs and server equipment, software including firmware is updated by way of a network or a medium such as a CD-ROM so as to cope with vulnerability in terms of security and malfunctions. However, in an image forming apparatus, firmware is updated after the image forming apparatus is stopped, and hence there is a time period (downtime) for which a user cannot use the image forming apparatus. The downtime compromises convenience for users and is thus desired to be reduced to the extent possible. The downtime is reduced by updating firmware in the background of an image forming apparatus or updating firmware in late night hours for which the image forming apparatus is not in use.
In particular, update of firmware in the background of an image forming apparatus is performed by “application of update firmware” in which firmware required for update (hereafter referred to as “update firmware”) is downloaded and temporarily expanded in the background of the image forming apparatus during normal operation, and when the image forming apparatus is restarted, firmware that has been applied up to that time is replaced with the temporarily expanded update firmware.
In this firmware update, downloaded update firmware is encrypted to prevent application of firmware that has been, for example, tampered with. Moreover, whether or not update firmware has been tampered with is checked before the update firmware is downloaded, temporarily expanded, and applied to an image forming apparatus, and when the update firmware has been tampered with, application of the update firmware is canceled to prevent application of firmware that has been tampered with (see, for example, Japanese Laid-Open Patent Publication (Kokai) No. 2006-323675).
However, update firmware that has been downloaded and temporarily expanded stays in an image forming apparatus until it is applied to the image forming apparatus, and the longer the time period for which the update firmware stays in the image forming apparatus, the higher the possibility that the encrypted update firmware will be decrypted. This decryption may tamper with the update firmware, or even after whether or not the update firmware has been tampered with is checked, the update firmware may be tampered with. As a result, improper firmware may be applied to the image forming apparatus.